Secure Cluster-Wise Time Synchronization in IEEE802.15.4e Networks

In IEEE802.15.4e networks, all nodes need to keep high-precision synchronization, which can enable highly reliable and low-power wireless networks. Cluster-wise time synchronization is usually necessary in IEEE802.15.4e networks, which provide a common time among a cluster of nodes. However, it cannot survive malicious attacks in hostile environments. We propose a secure cluster-wise time synchronization for IEEE802.15.4e networks. This paper makes three contributions: First, we provide an in-depth security analysis of cluster-wise time synchronization in IEEE802.15.4e networks. Second, we propose a security countermeasure which includes an improved μTESLA broadcast authentication protocol and fault-tolerant time synchronization algorithm. The improved μTESLA broadcast authentication protocol adopts a packet-based key chain mechanism to resolve the conflict between the delay of disclosed keys and the length of key chain in the original μTESLA. The fault-tolerant time synchronization algorithm adopts a cluster-wise time synchronization model to guarantee an upper bound of time difference between normal nodes in a cluster. Finally, theoretical analysis and real experiment results validate the effectiveness and feasibility of the security countermeasure.